Ideally, yes, one would prefer norms under 20 years old.
They likely do not provide norms against current examinees because they do not have the resources to do a nationally-representative re-norming like ETS did, and prefer not to use the convenience sample for norming, because it's self-selected, and not representative of the US population. CTY does have some experience using relatively aged out-of-level testing norms with GT populations, as a similar issue was involved with the old SATs, prior to the re-centering in 1995.
I wouldn't say it's totally useless information. You just have to understand the limits of the data.
